This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. With the characterization of the chimpanzee genome, there has been an increased interest in this species as a research model for fields as diverse as AIDS and behavioral studies. This, along with continued Yerkes support of research for which the species is uniquely suitable, requires careful monitoring and management of animal assignments, which is now underway. Given that most of our chimpanzees are housed socially, considerable effort is invested in contraception to prevent pregnancies. IUDs are the primary method of choice, with females unsuitable for IUD insertion receiving hormonal interventions for contraception or being housed in single-sex groups. Continued improvements to chimpanzee housing have included replacing wire mesh walls, improving doorway systems and providing additional environmental enrichment. These improvements facilitate animal welfare, animal husbandry, and chimpanzee research. Positive reinforcement training continues to be a high priority, including providing support to and working with Yerkes research personnel. The Center has a dedicated chimpanzee cognitive testing facility. The overall purpose of this project is to maintain and study a population of chimpanzees and to ensure availability of this species to appropriate NIH funded investigators.